Importance of Maintenance to Standby Generators

[CuriousElectron]

Hello,

How important is periodic maintenance to standby/prime generators located in industrial/office facilities if there are very infrequent outages at site and the generators are seldom called to run? Would it also depend on the fuel type used and as such the maintenance requirements are slightly different for each generator type?

Thank you for feedback.
Regards,
EE

 

[Hoxton]

As so often, this can take you into a maze of detail.

Think why the set was installed in the first place, is it regulatory, e.g. to permit safe evacuation, like from a football stadium at night, keeping the lights etc on?

Or is it commercial pressure, keeping a production line running, for example? So you keep the plant running during that rare power outage, and keep the revenue flowing.

There are basic maintenance issues, such as changing the lube oil, but most important in my view is to check that the set actually starts and takes load. Very often I find start batteries not charged, almost as common is the set being in ‘manual’ and not ‘automatic’, or the fuel valve being turned to ‘off’!

Most standby units are diesel fuelled, due to the reliability of supply, relatively easy storage etc. Smaller ones can be petrol. So fuel type is often not an issue.

The attached guidance notes take you through the issues.

 

[waross]

A good battery check is to disconnect the fuel solenoid and trigger an automatic start. Typically it will make three start attempts and then rest. Run two or three complete cycles and then reconnect the fuel solenoid and let the set start.
Use the results of this test and your judgement to determine when to change the batteries.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Bill West]

[link "In Florida, during Hurricane Charlie in 2004, the Federal Emergency Management Agency (FEMA) reported that 50% of standby generators failed."]

https://www.government-fleet.com/157049/how-to-maintain-stored-diesel-fuel

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The electrical and mechanical designers at our place took a long term theoretical view at system performance and felt the sets should be run monthly if not weekly otherwise there was just no confidence they would run when needed. Our operating staff never looked at it, their work urged a short term pragmatic view and they only dealt with maintainance and breakdowns.

Aside from batteries, diesel fuel life is an issue. After a year it's liable to water absorbtion and algae growth which will clog filters. Instead of letting it go stale and paying to take it away, burn it up with regular runs. How about running the set under at least 3/4 load, for at least an hour each time, and spacing the execises so that the whole fuel stock is used up in no more than say 8 months? Just guessing, but if the site has a lot of supply, 3-7 days?, this might lead to a practical neccesity of pumping it out to be used up elsewhere (company trucks?) every 6 months.

Bill

 

[crshears]

...diesel fuel life is an issue. After a year it's liable to water absorbtion and algae growth which will clog filters. Instead of letting it go stale and paying to take it away, burn it up with regular runs.

There are permanently installed fuel polishing systems on the market that purport to keep Diesel fuel in longer-term storage in "like-new condition" as one website states. It's been a while since I researched this, but IIRC one of these used rolls of toilet paper as an edge filter, reportedly to very good effect.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]